In recent years, Ethernet over SONET/SDH (EoS) has become a popular solution for carriers to transport data packets over long-haul Wide-Area Networks (WANs). This solution has been driven by a number of factors, including compatibility issues and pricing concerns. EoS allows for the utilization of already built and deployed SONET/SDH transport infrastructures and facilities, as well as operations, administration, and maintenance (OAM) features. For equivalent bandwidth, the per-interface price for Gigabit Ethernet (GigE) is approximately one quarter that of Time Division Multiplexing (TDM) (Packet-Over-SONET (POS)) interfaces.
One common misperception in this area has been that, by equipping a transport network element with an Ethernet interface card, the carriers would perform traditional layer-2 functions. While this may be the case in metro networks, this approach presents network management problems as service providers and customers typically use different tools and processes to manage their layer-2 and layer-1 networks and functions. Currently, for most carriers, Ethernet interfaces, including Fast Ethernet (100 Mb/s), Gigabit, and 10-Gigabit Ethernet interfaces, serve as cost-effective layer-1 alternatives for upgrading customers' bandwidth.
Traditionally, SONET/SDH transport networks have been known for their ready availability and high reliability. These transport networks are typically deployed for voice traffic transport. With recent advancements in SONET/SDH technology, including Generic Framing Procedure (GFP), Virtual Concatenation (VCAT), and LCAS, it is possible, via the methods and apparatuses of the present invention, that EoS transport data packets can achieve this same level of availability and reliability, and in a bandwidth-efficient manner.